Fabrication Method of MEMS Transducer Element

Abstract

A method of fabricating a plurality of individual microelectromechanical transducer elements includes forming a plurality of microelectromechanical transducer elements on a wafer. Each microelectromechanical transducer element has a sensitive region with a membrane and a sensing element monitoring at least one measurand and generating an electrical signal correlated with the at least one measurand, and an electrical contact outputting the electrical signal. The method includes providing, for each microelectromechanical transducer element, a sealing structure around a sensitive region and an electrical connection connected to the electrical contact. The sealing structure and the electrical connection are made out of a reflow solder material. The method includes dicing the wafer to form individual microelectromechanical transducer elements.

What is claimed is: 
     
         1 . A method of fabricating a plurality of individual microelectromechanical transducer elements, comprising the steps of:
 forming a plurality of microelectromechanical transducer elements on a wafer, each microelectromechanical transducer element has a sensitive region with a membrane and a sensing element monitoring at least one measurand and generating an electrical signal correlated with the at least one measurand, and an electrical contact outputting the electrical signal;   providing, for each microelectromechanical transducer element, a sealing structure around a sensitive region and an electrical connection connected to the electrical contact, the sealing structure and the electrical connection are made out of a reflow solder material; and   dicing the wafer to form individual microelectromechanical transducer elements.   
     
     
         2 . The method of  claim 1 , wherein, during the providing step, the sealing structure and the electrical connection are formed during a same process step. 
     
     
         3 . The method of  claim 1 , wherein the providing step includes providing the sealing structure and the electrical connection over a same surface side of the wafer. 
     
     
         4 . The method of  claim 1 , wherein the electrical connection and the sealing structure are disposed over opposite sides of the wafer. 
     
     
         5 . The method of  claim 1 , further comprising providing at least one via extending through the wafer per microelectromechanical transducer element. 
     
     
         6 . The method of  claim 1 , further comprising, before the dicing step:
 providing a substrate including a plurality of channels extending through the substrate;   aligning each channel with the sensitive region of one of the microelectromechanical transducer elements; and   attaching the substrate to the wafer using the sealing structures and the electrical connections to seal an interface between the sensitive regions and the substrate from a remaining region of the microelectromechanical transducer elements and to electrically connect the electrical contacts of the microelectromechanical transducer elements with a plurality of mating electrical contacts of the substrate.   
     
     
         7 . The method of  claim 6 , wherein the attaching step includes soldering the sealing structures and the electrical connections. 
     
     
         8 . The method of  claim 1 , further comprising providing an integrated snubber structure inside the wafer in the sensitive region. 
     
     
         9 . The method of  claim 1 , further comprising providing a groove in the wafer around the sensitive region. 
     
     
         10 . The method of  claim 9 , wherein the groove, after the providing step, is positioned between the sensitive region and both the sealing structure and the electrical connection. 
     
     
         11 . The method of  claim 1 , further comprising, prior to the dicing step, providing a channel in the wafer, the channel at least partially aligned with the sensitive region. 
     
     
         12 . A microelectromechanical transducer element, comprising:
 a sensitive region with a membrane and a sensing element on a transducer substrate monitoring at least one measurand and generating an electrical signal correlated with the at least one measurand, and an electrical contact outputting the electrical signal;   a sealing structure; and   an electrical connection made out of a same material as the sealing structure, the sealing structure and the electrical connection are provided on a same surface of the transducer substrate.   
     
     
         13 . The microelectromechanical transducer element of  claim 12 , wherein the sealing structure and the electrical connection are made of a solder material. 
     
     
         14 . The microelectromechanical transducer element of  claim 13 , wherein the sealing structure and the electrical connection are made of a reflow solder material. 
     
     
         15 . The microelectromechanical transducer element of  claim 12 , further comprising a via provided in the transducer substrate and connecting the electrical contact with the electrical connection. 
     
     
         16 . The microelectromechanical transducer element of  claim 12 , further comprising a channel within the transducer substrate. 
     
     
         17 . The microelectromechanical transducer element of  claim 16 , wherein the channel is in fluidic connection with the membrane. 
     
     
         18 . The microelectromechanical transducer element of  claim 17 , wherein the channel is a snubber structure. 
     
     
         19 . The microelectromechanical transducer element of  claim 12 , wherein the transducer substrate has a groove positioned between the sensitive region and both the sealing structure and the electrical connection. 
     
     
         20 . A microelectromechanical sensor arrangement, comprising:
 a microelectromechanical transducer element having a sensitive region with a membrane and a sensing element on a transducer substrate monitoring at least one measurand and generating an electrical signal correlated with the at least one measurand, and an electrical contact outputting the electrical signal, a sealing structure, and an electrical connection made out of a same material as the sealing structure; and   a substrate having a channel, the microelectromechanical transducer element is mounted on the substrate such that the media channel is in fluidic connection with the membrane of the sensitive region, the sealing structure surrounds the channel and is sandwiched between the microelectromechanical transducer element and the substrate and the electrical connection, the sealing structure electrically connects the microelectromechanical transducer element and the substrate.